1. Field of the Invention
The present invention relates to a piezoelectric actuator, an inkjet print head assembly, and a method of manufacturing the piezoelectric actuator and the inkjet print head assembly.
2. Description of the Related Art
In general, inkjet print heads have a structure in which an electric signal is converted into a physical force to allow ink to be ejected as droplets via small nozzles. Inkjet print heads may be classified into two types thereof, according to a method of ejecting ink utilized thereby. One is a thermally driven inkjet print head generating bubbles in ink by using a thermal energy and ejecting the ink by using expansive force of the bubbles, and another is a piezoelectric inkjet print head in which a piezoelectric body is deformed to form pressure to supply ejection force to ink.
Particularly, piezoelectric inkjet print heads are generally used in industrial inkjet printers. For example, piezoelectric inkjet print heads are used to directly form circuit patterns by jetting ink formed of a molten metal such as gold or silver onto a flexible printed circuit board (FPCB), are used to manufacture industrial graphics, liquid crystal displays (LCDs), and organic light emitting diodes (OLED), as well as for solar cells.
Piezoelectric inkjet print heads have a structure in which a piezoelectric actuator is included on a top of an inkjet print head plate including a pressure chamber to apply pressure to ink filling the pressure chamber. In this case, it is necessary to electrode-wire a driving electrode of the piezoelectric actuator to supply a voltage thereto.
Piezoelectric inkjet print heads use films formed by applying and solidifying a piezoelectric liquid in a paste state or piezoelectric films obtained by forming of piezoelectric bodies having a film shape (hereinafter, all referred to as a piezoelectric film, in which a piezoelectric film is formed to have a shape corresponding to a pressure chamber formed to be extended in a longitudinal direction and an upper electrode corresponding to a shape of each of the pressure chambers is included on a top of the piezoelectric film.
In this case, as an inkjet printing technology with high resolution is needed, it is necessary to temper the pressure chamber to embody nozzles having a high degree of integration.
In such situation, it is difficult to connect an FPC to supply power to the upper electrode and also a defect such as a short circuit may occur although being connected.
For this, a technology for preventing the occurrence of such a short circuit by manufacturing a piezoelectric film having a novel shape is provided.